The al Qaeda commander who led the deadly assault on the In Amenas gas plant in Algeria has been killed, according to the Chad military.

Armed forces from Chad say Mokhtar Belmokhtar was killed when they targeted and destroyed a terrorist base in northern Mali.

The death of one of the world's most wanted jihadists would be a major blow to al Qaeda in the region and to Islamist rebels already forced to flee towns they had seized in northern Mali by an offensive by French and African troops.

"On Saturday, March 2, at noon, Chadian armed forces operating in northern Mali completely destroyed a terrorist base," Chadian armed forces spokesman General Zacharia Gobongue said in a statement read on national television.

"The toll included several dead terrorists, including their leader Mokhtar Belmokhta."

Foreign Secretary William Hague hailed the reported killing as a "blow to terrorism". He told the BBC: "It would be a blow to terrorism and to the criminal network around this man and other people."

Image Caption:More than 60 people were killed in the attack on the In Amenas gas plant

Belmokhtar claimed responsibility for the seizure of dozens of foreign hostages at the In Amenas gas plant in Algeria in January in which more than 60 people were killed.

The report of his death comes days after Chad's President Idriss Deby said soldiers in Mali had killed another leading al Qaeda commander in the Sahara, Adelhamid Abou Zeid.

French officials said they could not confirm the killing of either Abou Zeid or Belmokhtar.

Sky's foreign affairs editor Tim Marshall said that if his death is confirmed, al Qaeda in North Africa will have been deprived of "one of the most battle-hardened leaders".

The Foreign Office says it is aware of the reports and is looking into them.

Algerian-born Belmokhtar has been fighting as an Islamist militant for more than two decades.

He claimed to have received military training in Afghanistan before returning to Algeria, where he lost an eye fighting in the Islamist insurgency in the 1990s.

He then joined AQIM - which operates across the Sahara - before breaking off to lead his own group.

He is also known as Mr Marlboro because of his alleged role in cigarette smuggling in the region.

Chad is one of several African nations that have contributed forces to a French-led military intervention in Mali aimed at ridding its vast northern desert of Islamist rebels who seized the area nearly a year ago following a coup in the capital.

Western and African countries are worried that al Qaeda could use the zone to launch international attacks and strengthen ties with African Islamist groups like al Shabaab in Somalia and Boko Haram in Nigeria.